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Biomedical subjects

C Kohler

Publications and source records attributed to C Kohler.

At least 37 records · Page 2Linked to original sources

Regeneration of bone graft donor sites.

When crestal volume is greatly insufficient for the placement of dental implants, bone grafting is usually the most reliable ridge augmentation procedure. The grafts are most often taken in parietal or mandibular symphysis regions. Though not too noticeable, it seems contra-indicated and even potentially dangerous to leave zones like the cranium to repair spontaneously. Guided bone regeneration techniques have shown their ability to regenerate new bone under difficult conditions in jaws. Their use in bone graft donor sites is simple and the results are consistent. This report shows that 2 types of resorbable membranes are equally as efficacious in terms of new-bone formation.

Adult↗

Depression in temporal lobe epilepsy before epilepsy surgery.

PURPOSE: This study examined the association of depression with laterality of epilepsy surgery in patients with temporal lobe epilepsy before standard lobectomy. METHODS: Forty-nine patients presented for EEG telemetry for localization of epilepsy and eventual temporal lobectomy. Patients underwent routine neuropsychiatric evaluation blinded for epileptic focus, including ratings on depression. Patients were grouped according to right (n = 25, M = 10/F = 15) and left (n = 24, M = 13/F = 11) temporal lobectomy. Analysis of variance included side of surgery as grouping variable and sex, general depressive, cognitive depressive, and vegetative depressive symptoms as dependent variables. Chi2 analyses included categoric variables of sex, handedness, education, neuropathologic findings, and current affective disorders. t Tests were performed on variables of age, epilepsy duration, and cognitive function. RESULTS: Right and left temporal epilepsy groups did not differ with regard to sex, handedness, age, duration of epilepsy, education, cognitive function, and neuropathology. Patients with right temporal epilepsy rated higher on general, cognitive. and vegetative depression scores. Women scored higher on general, cognitive, and vegetative depression scores. Current affective disorders were more common in the right temporal epilepsy group. CONCLUSIONS: Depression ratings and diagnoses were more prominent in patients with right temporal lobe epilepsy and in women in particular. The strength of this laterality finding lies in the selection of patients, as all underwent epilepsy surgery. The finding on gender difference partly reflects the higher incidence of depression in women and needs further exploration. The laterality finding contrasts with recent findings in epilepsy, stroke, and trauma that associate depression with left hemispheric lesions. However, our results are consistent with findings in electrically hyperactive lesions such as gelastic and dacrystic epilepsy.

Adolescent↗

[The nursing diagnosis of "spiritual distress", a necessary re-evaluation].

The subject of the study consisted in identifying the spiritual needs of the terminally ill patients, so as to investigate and specify the implementation field of the diagnosis of "spiritual distress" by the French nurses relative to the values and beliefs. The key moments, when the spiritual needs can express themselves also had to be spotted, in order to investigate the possible role of the nurse faced with the spiritual needs of the patients. The study was carried out on a population of 27 AIDS and cancer patients, hospitalized in two units of palliative cares of the Paris region and on a population of 20 nurses of these same units. It was made during the year 1996 by means of interviews with patients, comprising 51 open or half-open questions and questionnaires for nurses, comprising 20 questions. These tools have been structured on the basis of 4 main lines namely spirituality, religion, the ill being called "spiritual distress", nursing diagnosis (for the nurses). The results from the patients show that nearly all of them have had a feeling of ill being which would be of spiritual nature, where existential questioning prevails concerning the meaning of life, of death, of pain, of illness whereas only slightly more than a third of the nurses think that it happens frequently to the patients. The spiritual distress can be described as the failure of giving a meaning to one's life. Religion is mainly evoked in terms of rites with "mosaic" beliefs specific to each individual. The big majority of the nurses concerned by this study have an intuitive knowledge of the main features of the nursing diagnosis of "spiritual distress". This knowledge does not seem to be linked really to the training they had, but rather to their professional experiences and maybe to the personal life story. This nursing diagnosis does not seem to be adapted to our western culture. Its lack of discriminatory power and of flexibility does not make it very useful for the caretaker who needs to clarify beforehand the concepts of spiritual needs and of religious needs. As for the actions, the appeal to the religion representatives or to the psychologist is not always what the patients want even though the ill being appears mainly when the patients feel lonely ... we therefore resort to actions of relation of help with an active listening and help to the rereading of life for which the nurse is in a rather good position, according to the patients.

Adult↗

Vitamin C improves endothelial function of conduit arteries in patients with chronic heart failure.

BACKGROUND: Chronic heart failure (CHF) is associated with endothelial dysfunction including impaired endothelium-mediated, flow-dependent dilation (FDD). There is evidence for increased radical formation in CHF, raising the possibility that nitric oxide is inactivated by radicals, thereby impairing endothelial function. To test this hypothesis, we determined the effect of the antioxidant vitamin C on FDD in patients with CHF. METHODS AND RESULTS: High-resolution ultrasound and Doppler was used to measure radial artery diameter and blood flow in 15 patients with CHF and 8 healthy volunteers. Vascular effects of vitamin C (25 mg/min IA) and placebo were determined at rest and during reactive hyperemia (causing endothelium-mediated dilation) before and after intra-arterial infusion of N-monomethyl-L-arginine (L-NMMA) to inhibit endothelial synthesis of nitric oxide. Vitamin C restored FDD in patients with heart failure after acute intra-arterial administration (13.2+/-1.7% versus 8.2+/-1.0%; P<.01) and after 4 weeks of oral therapy (11.9+/-0.9% versus 8.2+/-1.0%; P<.05). In particular, the portion of FDD mediated by nitric oxide (ie, inhibited by L-NMMA) was increased after acute as well as after chronic treatment (CHF baseline: 4.2+/-0.7%; acute: 9.1+/-1.3%; chronic: 7.3+/-1.2%; normal subjects: 8.9+/-0.8%; P<.01). CONCLUSIONS: Vitamin C improves FDD in patients with CHF as the result of increased availability of nitric oxide. This observation supports the concept that endothelial dysfunction in patients with CHF is, at least in part, due to accelerated degradation of nitric oxide by radicals.

Administration, Oral↗

Depression in schizophrenia: I. Association with neuropsychological deficits.

BACKGROUND: The presence of depression in schizophrenia has been well described with regard to stage and symptoms of illness; however, little is known about the possible etiology. METHODS: In an effort to advance the understanding of the neurobiology of depression in schizophrenia, we grouped patients with schizophrenia based on their ratings on the 21-item Hamilton Depression Rating Scale. There were 63 patients (35 men, 28 women) in the high (> or = 18) depression group and 81 patients (52 men, 29 women) in the low (< 18) depression group. The groups were compared in demographic, clinical, and eight neuropsychological domains. RESULTS: The two groups differed in age at onset of illness, severity of delusions, and performance in a single neuropsychological domain: attention. The specific component of impaired attention was vigilance, with poorest performance seen in women with higher depression scores. CONCLUSION: The presence of specific attentional impairment associated with depressive symptoms in schizophrenia is consistent with the hypothesis of frontal lobe dysfunction in depression, because these regions have been implicated in attentional processes.

Adult↗

Depression in schizophrenia: II. MRI and PET findings.

BACKGROUND: Despite consistent descriptions of depressive symptoms in schizophrenia, little is known about their neurobiology. The purpose of this study was to examine the association of depression in schizophrenia with measures of brain anatomy and metabolism. METHODS: Seventy-nine patients were grouped according to their ratings on the Hamilton Depression Rating Scale (HDRS): > or = 18 was the cutoff between the "high" and "low" depression groups. All patients underwent clinical and magnetic resonance imaging (MRI) evaluation, and a subsample of 37 underwent 2-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) measurements of cerebral glucose metabolism. RESULTS: The high depression group had larger bilateral temporal lobe volumes and decreased laterality (left minus right of metabolism in the anterior cingulate). CONCLUSIONS: The neurobiology of depression in schizophrenia thus seems to share features with major depression due to other disease states.

Adult↗

Automated cell count in flow cytometry: a valuable tool to assess CD4 absolute levels in peripheral blood.

The enumeration of lymphocyte subsets in absolute counts has long relied on different methods applied separately to whole blood cell count, lymphocyte differential appreciation, and flow cytometric evaluation of lymphocyte subsets percentages. The development of multicolor labeling methods inflow cytometry now allows a more homogeneous appreciation of several cell subsets among gated lymphocytes. The use of internal calibrators, such as microbead suspensions, also permits a direct appreciation of subsets in absolute counts in a single-platform method. These methods were compared with a traditional multiplatform method of assessing absolute counts of lymphocyte subsets in a pilot study in which all manipulations were performed by 1 person and in a full-scale larger study performed in the normal working conditions of a hospital laboratory. Microspheres seem to be a reliable tool to perform absolute count enumeration inflow cytometry, but several precautions in the sample preparation and flow cytometric analysis are required.

Antibodies, Monoclonal↗

Psychosis Secondary to Brain Tumor.

Brain tumors may present with psychotic symptoms that resemble schizophrenia. Although psychosis secondary to brain tumor is relatively rare, the frequent lack of neurological findings can lead to misdiagnosis. Psychosis secondary to brain tumor is more common and also harder to accurately diagnose in the elderly. Key aspects of the epidemiology, clinical spectrum, diagnostic evaluation, and treatment are reviewed. The case of a 26-year old woman with psychosis secondary to a meningioma of the right lateral ventricle with extension into the corpus callosum and periventricular white matter is presented. Symptoms completely resolved after surgical excision of the tumor and remain in remission at 2(1/2) year follow-up on no medications. The clinician should maintain a high degree of vigilance for clinical features suggestive of this potentially reversible cause of psychosis.

Journal Article↗

Role of bradykinin in mediating vascular effects of angiotensin-converting enzyme inhibitors in humans.

BACKGROUND: The angiotensin-converting enzyme (ACE) not only generates angiotensin II but is also the main enzyme that destroys bradykinin. It has been hypothesized, therefore, that bradykinin is involved in the vascular effects of ACE inhibitors. However, its contribution has never been demonstrated in humans because of the lack of specific bradykinin receptor antagonists. METHODS AND RESULTS: High-resolution ultrasound and Doppler were used to measure radial artery diameter and blood flow in 10 healthy volunteers. The vascular effects of the ACE inhibitor quinaprilat, the selective bradykinin B2-receptor antagonist icatibant, and their combination were determined at rest, during reactive hyperemia (with increased flow causing endothelium-mediated, flow-dependent dilation), and during sodium nitroprusside, causing endothelium-independent dilation. Neither icatibant nor quinaprilat affected arterial diameter or blood flow at rest. However, icatibant reduced flow-dependent dilation by 33%, and quinaprilat increased flow-dependent dilation over baseline by 46%. After coinfusion of quinaprilat and icatibant, flow-dependent dilation was reduced to a similar extent as after infusion of icatibant alone. CONCLUSIONS: ACE inhibition enhances flow-dependent, endothelium-mediated dilation in humans by a bradykinin-dependent mechanism. This observation indicates that accumulation of endogenous bradykinin is involved in the vascular effects of ACE inhibitors in humans.

Adult↗

Effects of dopamine D-1 and D-2 receptors on intraocular pressure in conscious rabbits.

This investigation was designed as a randomized, placebo-controlled, double-masked, crossover study in NZW rabbits with normal intraocular pressure (IOP) to investigate dopaminergic effects on IOP. SKF 38393, a selective D1-receptor agonist, increased, and SDZ PSD-958, a selective D1-receptor antagonist, decreased IOP, respectively. The selective D2-receptor agonist quinpirole decreased IOP, whereas the selective D2 receptor antagonist metoclopramide had no significant effect. Combinations of quinpirole with SDZ PSD-958 decreased IOP in an additive manner. SDZ GLC-756, a mixed D1-receptor antagonist/D2-receptor agonist, decreased IOP in a dose-dependent manner with a maximum effect greater than the maximum effects produced either by the D1-receptor antagonist SDZ PSD-958 and the D2-receptor agonist quinpirole. The effect of SDZ GLC-756 could only be partially blocked by the selective D2-receptor antagonist metoclopramide suggesting that both D1-receptor blockade and D2-receptor stimulation participate in its IOP-lowering effect. Tonography suggests that SDZ GLC-756 has no significant effect on outflow facility. Furthermore, the results suggest that both D1 and D2 receptors each play an independent role in the regulation of IOP in rabbits. Thus, simultaneous blockade of D1 receptors and stimulation of D2 receptors may provide a new pharmacological approach for the treatment of ocular hypertension frequently associated with glaucoma.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

Sequential assessment of cell cycle S phase in flow cytometry: a non-isotopic method to measure lymphocyte activation in vitro.

Lymphocyte multiplication can be induced in vitro by mitogens or specific antigens, and is usually measured using isotopic methods involving tritiated thymidine. Cellular proliferation can also be analyzed by flow cytometry techniques based on cell cycle analysis through the measurement of DNA content. We applied this method to lymphocytes from 113 individuals, to evaluate lymphocyte proliferation after stimulation in vitro by a mitogen (phytohaemagglutinin, PHA) or a recall antigen (tetanus toxoid), using a kinetic approach with four points sequential measurements of the S and G2 phases over six days of culture. The proportion of cells in S phase after PHA stimulation was significantly higher than in controls overall and as early as on day three of the culture. Activation with a recall antigen significantly induced increasing S phase cell proportions up to day six. These data suggest that flow cytometric assessment of the S phase could be a useful alternative to isotopic methods measuring lymphocyte reactivity in vitro.

Adult↗

Postictal language dysfunction in patients with right or bilateral hemispheric language localization.

PURPOSE: As shown previously, when temporal lobe complex partial seizures (TLCPS) originate from the language dominant hemisphere, patients cannot read a test phrase correctly within 60 s of the end of the ictal discharge. We wished to assess whether postictal language testing results discordant with this pattern identified patients with non-left (right hemisphere or mixed) language dominance. METHODS: Since 1988, all patients undergoing video/EEG monitoring at our institution have been given a test phrase to read aloud as soon as a seizure is detected. Inclusion criteria for this study were (a) postictal language testing within 60 s of seizure end for at least one TLCPS, (b) > 90% seizure reduction after anterior temporal lobectomy with 2-year minimum follow-up, and (c) language localization by either intracarotid amobarbital test (IAT) or direct electrical stimulation of left hemisphere cortex. RESULTS: Two hundred twenty-four seizures in 64 patients were analyzed. Discordant postictal language patterns were noted in 10 of 11 patients with IAT documented non-left language dominance and in 15 of 53 with left dominance (p = 0.006; sensitivity 90.9%, specificity 71.7%). CONCLUSIONS: Postictal language testing accurately identifies patients with non-left language dominance and may be useful in selecting appropriate patients for IAT.

Adult↗

Occupational rhinitis and asthma to latex.

Occupational allergic rhinitis to proteins is increasing in importance. Two cases of latex-induced rhinitis are reported in a nurse's aid and a laboratory technician. A crossed food allergy is quoted. Positive prick-tests and specific IgE to latex have been demonstrated in both cases. A double-blind nasal challenge test has been performed with the rinse fluid from a brand of latex gloves. Clinical manifestations with endoscopic modifications of the nasal mucosa have been observed. A rise in nasal secretory eosinophilia has been demonstrated. The authors wish to draw attention to this new aetiology of occupational rhinitis insofar as it precedes the onset of work-related asthma as shown in one case. The eviction of wearing gloves is not sufficient as latex allergens are airborne. The eviction of ordinary latex gloves must be extended to all other workers in the same place and the use of powder-free gloves is advisable.

Adult↗

[Electron microscopic studies of the action of erythromycin, doxycycline and ofloxacin on the growth cycle of Chlamydia trachomatis].

The aim of this work is to realise an ultra structural study of the action of antibiotics (doxycycline, erythromycin and ofloxacin) on the intracellular growth cycle of chlamydia. All assays were done on McCoy cells. Antibiotics were added to the culture medium two hours after inoculation with C. trachomatis. 24 and 48 hours, cells were removed and treated by standard procedure for transmission electron microscopy. No difference between control-cells and cells treated with doxycycline, erythromycin (0.015 mg/l) and ofloxacin (0.15 mg/l), was observed in the inclusions (number and size). However 48 hours, the quantity of elementary bodies (E.B.) was lower in treated culture. The organisms were not morphologically different from those seen in untreated culture. At higher concentrations of doxycycline and erythromycin (0.03 mg/l - 0.06 mg/l), the inclusions were smaller. Reticulate bodies (RB) were each in separate inclusion indicating that no fission has taken place. At 48 hours, no infectious forms (EB) were observed. Small or large RBs appeared with an apparent normal cytoplasmic membrane within an inflated cell wall. With ofloxacin (0.3 - 0.6 mg/l), inclusions contained enlarged and sometimes empty bacterial cells. Doxycycline and erythromycin (0.03 mg/l) inhibit the division of RBs and there maturation to EBs Ofloxacin (0.3 mg/l) induces the production of large abnormal forms which may not be able to revert towards viable bacteria.

Cell Division↗

Allergy and intolerance to flavouring agents in atopic dermatitis in young children.

The role of flavouring was studied in eleven children under five years of age suffering from severe atopic dermatitis. In all cases, the dietary questionnaire showed the high daily intake of natural vanilla, vanillin, natural and artificial flavouring. Double-blind oral provocation tests were carried out with balsam of Peru (225 mg), natural vanilla (50 mg), artificial vanillin (12.5 mg). Nine children out of eleven presented eczematous reactions, one a Quincke's oedema. Two challenges remained negative. The eviction of food flavouring agents brought about a clear improvement in six children. The authors point out the risk of increasing consumption of flavouring agents, and bring into question the traditional attitude of considering food flavouring agents as innocuous.

Allergens↗

Effect of a series of 1-alkyl ether lipids on inhibition of phospholipase A2 activity and PAF responses.

Several 1-alkyl ether lipids were studied for their ability to inhibit PLA2 and antagonize PAF responses. Studies with synthetic micellar substrate (1-stearyl-2-arachidonyl phosphocholine), at concentrations ranging from 0.02 to 1000 microM, demonstrate that CL 118326 inhibits porcine pancreatic PLA2 in vitro. As the substrate concentration increases, there is a dose-dependent increase in the IC50 value (IC50 ranges: 1.6-84.6 micrograms/ml or 2.6-137 microM). CL 118326 inhibits mammalian pancreatic PLA2, but not snake or bee venom PLA2. CL 118326 inhibits thrombin (IC50 = 7.9 microM), but not Na arachidonate- (IC50 > 100 microM) induced platelet aggregation, indicative of inhibition of cellular PLA2. CL 118326 inhibits other PLA2-dependent processes such as antigen-induced leukotriene (LTC4) release (IC50 = 2.3 micrograms/ml or 3.8 microM) and histamine release (IC50 = 1.4 micrograms/ml or 2.2 microM) in basophil-enriched WBCs. Intradermal coinjection of CL 118326 (10 micrograms) with PLA2 into guinea pig skin inhibits pancreatic PLA2-induced increase in vascular permeability and leakage, but not snake or bee venom PLA2-induced leakage. CL 118326 shows no PAF-like agonist activity in stimulating rabbit platelet-rich plasma. It inhibits PAF-induced aggregation (IC50 = 5.8 microM), but not ADP-induced aggregation. CL 118326 has greater efficacy as a PLA2 inhibitor than as a PAF antagonist since the IC50-substrate concentration ratio for PLA2 inhibition is < or = 1.0 at substrate concentrations of 10-1000 microM while the IC50-agonist ratio for PAF antagonism is > 100. Results for four other compounds related to CL 118326 are also presented.

Animals↗

Prospective study of risk factors in natural rubber latex hypersensitivity.

Five hundred sixty-nine subjects routinely underwent skin prick tests for latent sensitization to latex. The study of risk factors included skin tests to inhalant allergens, to diagnose atopy, and a questionnaire aimed at revealing frequent exposure to latex such as the wearing of gloves, multiple surgical procedures, or urinary catheterization. The subjects were categorized into five groups: group I, subjects with no risk factor (n = 272); group II, nonatopic subjects exposed to latex (n = 73); group III, atopic subjects not exposed (n = 180); group IV, exposed atopic subjects (n = 44); and group V, subjects with a history of intraoperative anaphylactic shock caused by latex (n = 13). Twenty-five subjects had spina bifida and were in either group II (14 subjects) or group IV (11 subjects). The questionnaire identified a probable allergy to latex in 18 subjects: 16 cases were confirmed by skin test, but responses were not informative in 23 patients who were sensitive to latex. Positive prick tests to latex were obtained in 0.37% of group I, 6.85% of group II, 9.44% of group III, and 36.36% of group IV. Of the children with spina bifida, 32% had positive skin test results. As risk factors, atopy and exposure were synergistic. We recommend predictive prick tests not only in children with spina bifida but also in any atopic subject or in any patient with a history of frequent exposure to latex. Latex could be considered a habitual allergen. The use of latex urinary catheters should be avoided in patients who are catheterized on a daily basis.

Adolescent↗